Fix the multiple instences of NetworkProviderSettingsActivity issue

- Use the command "adb shell dumpsys window" to dump how many
activities/windows currently on the system.
  Then search for section like "Task display areas in top down Z order"

Bug: 191956700
Test: manual test
Use "adb shell dumpsys window" to check no more multiple instences

Change-Id: Ie9e04db3db601fbeee9beceedb81929cd6eba439